1. Field of the Disclosure
This invention relates in general to threaded tubular connections, such as for large diameter pipes used in offshore hydrocarbon drilling and production operations, and particularly to a device to prevent rotation of tubular members after they are made up.
2. Background of the Disclosure
Hydrocarbon production wells can have several strings of casing of differing diameters cemented in the well. Each casing string can be made up of joints of pipe having threaded ends that are secured together. The portion of the connector having internal threads is commonly known as a female connector or box. The portion of the connector having external threads is commonly known as a male connector or pin. Some casing joints have a pin member at a first end and a box member at a second end. Normally, the operator relies on the friction of the made-up joint to prevent the threaded connectors from loosening while running the string into the well. With larger diameter casing, for example, from 16 inch to 36 inch, the friction of the made-up connector may be inadequate to prevent loosening while running the casing.
Operators have employed anti-rotation keys to prevent loosening. Some current anti-rotation key designs require specialty tools to install the locking mechanism. Some designs require explosive powered guns to set the locking mechanism. Other designs can be difficult to unlock in the event it is necessary to unscrew the pipe connection. Other current anti-rotation key designs require drilling a hole for the locking member after the pipe connection is made up. Drilling can result in metal shavings falling down the pipe string, which can cause issues. Further, drilling a made up pipe connection requires a complex drill. If disconnected, then reconnected, it may be necessary to drill another hole, and that hole may overlap the previously drilled hole, limiting the locking capacity.
In other current casing setups, the anti-rotation key can be inserted through a hole in the box and a hammer or wrench may be employed to position and secure the key. The anti-rotation key of such systems can have teeth that bite into the connector members, either upon insertion or when the pin starts to rotate out of the box, applying an axial compressive load on the connector members and permanently deforming the connector members in order to prevent relative rotation between the box and the pin. This may also affect the connector load path and initial loading condition and result in a reduction of cyclic load life.